Unsaturation in binuclear cyclopentadienylchromium carbonyl thiocarbonyls: Viability of (η-C5H5)2Cr2(CS)2(CO)3 in contrast to (η-C5H5)2Cr2(CO)5

The cyclopentadienylchromium carbonyl thiocarbonyls Cp₂Cr₂(CS)₂(CO)_n (n = 4, 3, 2, 1) have been studied by density functional theory using the B3LYP and BP86 functionals. The lowest energy Cp₂Cr₂(CS)₂(CO)₄ structure can be derived from the experimentally characterized unbridged Cp₂Cr₂(CO)₆ structure by replacing the two terminal carbonyl groups furthest from the Cr-Cr bond with two terminal CS groups. The two lowest energy Cp₂Cr₂(CS)₂(CO)₃ structures have a single four-electron donor η²-μ-CS group and a formal Cr-Cr single bond of length ∼3.1 Å. In contrast to the carbonyl analogue Cp₂Cr₂(CO)₅ these Cp₂Cr₂(CS)₂(CO)₃ structures are viable with respect to disproportionation into Cp₂Cr₂(CS)₂(CO)₄ and Cp₂Cr₂(CS)₂(CO)₂ and thus are promising synthetic targets. The lowest energy Cp₂Cr₂(CS)₂(CO)₂ structures have all two-electron donor CO and CS groups and short CrCr distances around ∼2.3 Å suggesting the formal triple bonds required to give the chromium atoms the favored 18-electron configurations. These Cp₂Cr₂(CS)₂(CO)₂ structures are closely related to the known structure for Cp₂Cr₂(CO)₄. In addition, several doubly bridged structures with four-electron donor η²-μ-CS bridges are found for Cp₂Cr₂(CS)₂(CO)₂ at higher energies. The global minimum Cp₂Cr₂(CS)₂(CO) structure is a triply bridged triplet with a CrCr triple bond (2.299 Å by BP86). A higher energy singlet Cp₂Cr₂(CS)₂(CO) structure has a shorter Cr-Cr distance of 2.197 Å (BP86) suggesting the formal quadruple bond required to give each chromium atom the favored 18-electron configuration.     

Crystal structure of [(C5Me4Et)3Rh3(μ3-Se)2](PF6)2CH3CN and [(C5Me4Et)2Rh2(μ2-Cl)3]PF6

The crystal structure of [(C₅Me₄Et)₃Rh₃(μ₃-Se)₂](PF₆)₂ and [(C₅Me₄Et)₂Rh₂(μ₂-Cl)₃]PF₆, obtained in the reaction of [(C₅Me₄Et)Rh(C₆H₆)](PF₆)₂ with ZnSe in 4M HCl under hydrothermal conditions, is determined. In agreement with the 18VE rule, the triangular cluster contains single metal-metal bonds (Rh-Rh 2.864(1) ?), whereas they are absent in the binuclear complex (Rh ...Rh 3,216(1) ?). Original Russian Text Copyright ? 2009 by P. A. Abramov, M. N. Sokolov, A. V. Virovets, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 1, pp. 169–172, January–February, 2009.     

[Gd2(Gly)6(H2O)4](ClO4)6(H2O)5的合成、晶体结构与热化学研究

利用微波技术合成了配合物[Gd₂(Gly)₆(H₂O)₄](ClO₄)₆(H₂O)₅, 进行了化学成分分析、红外表征和热重分析. 应用X衍射仪测定其晶体结构, 该晶体为一维链结构, 属三斜晶系, P 空间群, 晶胞参数: a＝1.1569(17) nm, b＝1.4138(2) nm, c＝1.5642(2) nm, α＝96.910(2)°, β＝102.735(2)°, γ＝105.512(2)°, V＝2.3606(6) nm³, Z＝2, D_c＝2.144 g•cm^－3. 采用精密溶解-反应量热计, 通过设计热化学循环, 计算出了该配合物的标准摩尔生成焓为 －(7960.73±3.23) kJ•mol^－1.     

Synthesis,structure characterization and thermal properties of [Zr6(μ3-O)4(μ3-OH)4(OOCCH2Bu)9(μ2-OH)3]2

Oxo/hydoxo zirconium(IV) complex of the general formula [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ has been isolated, when Zr(OⁱPr)₄ reacted with a 2-fold excess of 3,3-dimethylbutyric acid. Single crystal X-ray diffraction data, collected at 103 and 153 K, showed that the studied compound crystallizes in hexagonal system (P6₃/m (no. 176)). Structure consists of dimers composed of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉] sub-units, linked by six μ₂-OH bridges. Infrared spectroscopic studies proved the presence of hydroxo groups in the structure of studied clusters and formation of different types of oxo/hydroxo bridges. The application of variable temperature infrared spectroscopy and differential scanning calorimetry revealed that the structure of this complex undergoes the phase transitions at 143–183 and 203–293 K. Comparison of spectral and crystallographic data suggests that these phase transitions might be related to changes in the strength of Zr–O bonds of μ₂-OH bridges linking complex sub-units, and change in symmetry of the crystal lattice (from hexagonal to trigonal). Analysis of thermogravimetric data showed that decomposition of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ proceeds with complete conversion to ZrO₂ (monoclinic form) between 603 and 803 K.     

用Co(naph)2-Al2(C2H5)3Cl3-P(OPh)3催化体系合成中乙烯基液体聚丁二烯

为获得适中乙烯基含量的液体聚丁二烯为目的, 对Co(naph)2-Al2(C2H5)3Cl3-P(OPh)3催化体系进行了较为系统的研究, 考察了该体系的催化剂配比、浓度及供电子试剂对分子量、微观结构和转化率的影响. 实验结果表明, 该体系在一定的条件下可以制备出分子量在700~3500、1,2结构含量在35%~40%且转化率高于55%的液体聚丁二烯.     

Zr 5Ir 2In 4 – A Superstructure of the Lu 5Ni 2In 4 Type

Zr₅Ir₂In₄ was synthesized by reaction of the elements in a glassy carbon crucible in a water-cooled sample chamber of an induction furnace. The sample was characterized by X-ray diffraction on both powder and single crystals. Zr₅Ir₂In₄ crystallizes with a pronounced Lu₅Ni₂In₄ type subcell, space group Pbam, a=1739.5(6), b=766.3(2), c=338.9(2) pm. Weak additional reflections force a doubling of the subcell c axis. The superstructure of Zr₅Ir₂In₄ is of a new type: Pnma, a=1739.5(6), b=677.8(2), c=766.3(2) pm, wR2=0.0529, 1592 F² values, and 60 variable parameters. The group-subgroup scheme for the klassengleiche symmetry reduction is presented. The formation of the superstructure is most likely due to a puckering effect (size of the iridium atoms). The crystal chemistry of Zr₅Ir₂In₄ is briefly discussed.     

The preparation and crystal structure of (η-C5H5)(OC)3Mo(CH2)3C6H5

The reaction of with p-CH₃C₆H₄S(O)₂O(CH₂)₃C₆H₅ produces (η⁵-C₅H₅)(OC)₃Mo(CH₂)₃C₆H₅. This is only the second structurally characterized organometallic species in which an aromatic moiety is separated by three or more methylene groups. The alkyl chain adopts a staggered conformation, the Mo-C(1)-C(2)-C(3)-C(4) unit is nearly coplanar, and the alkyl chain eclipses the trans-carbonyl group on Mo. NMR evidence indicates that this conformation is preserved in solution.     

Synthesis and crystal structure of new one-dimensional copper(II) complex [Cu4(En)2(μ1,1-N3)4(μ1,1,1-N3)2(μ1,3-N3)2]n

A new polymer azido-bridged copper(II) complex [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂] _n (I) (En = ethylenediamine) has been synthesized and crystallography characterized. Complex I shows one-dimensional coordination polymeric structure based on a tetranuclear cluster unit [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂], in which the azido ions display three different bridging modes.     

Stepwise addition of CuBr at [(dtc)2Mo2(S)2(μ-S)2] (dtc=diethyldithiocarbamate): syntheses and crystal structures of two Mo/Cu/S clusters [(dtc)2Mo2(μ3-S)(μ-S)3(CuBr)] and [(dtc)2Mo2(μ3-S)4(CuBr)2]

Reactions of [(dtc)₂Mo₂(S)₂(μ-S)₂] with one or two equivalents of CuBr in CH₂Cl₂ afforded two new heterobimetallic sulfide clusters, [(dtc)₂Mo₂(μ₃-S)(μ-S)₃(CuBr)] (1) and [(dtc)₂Mo₂(μ₃-S)₄(CuBr)₂] (2). Both compounds were characterized by elemental analysis, IR, UV-vis and X-ray analysis. Compound 1 contains a butterfly-shaped Mo₂S₄Cu core in which one CuBr unit is coordinated by one bridging S and two terminal S atoms of the [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety. In the structure of 2, one [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety and two CuBr units are held together by six Cu-μ₃-S bonds, forming a cubane-like Mo₂S₄Cu₂ core.     

Mixed-ligand complexes [Cd(DMSO)5(NCS)][Cr(NH3)2(NCS)4] · 3DMSO and [Mn(DMSO)4(H2O)2][Cr(NH3)2(NCS)4]2 · 6DMSO · 2H2O: Syntheses and crystal structures

New mixed-ligand coordination compounds[Cd(DMSO)₅(NCS)][Cr(NH₃)₂(NCS)₄] · 3DMSO (I) and [Mn(DMSO)₄(H₂O)₂][Cr(NH₃)₂(NCS)₄]₂ · 6DMSO · 2H₂O (II) have been synthesized and studied by IR spectroscopy and X-ray diffraction analysis. The crystals of compound I are monoclinic, a = 14.5275(7), b = 23.1692(11), c = 14.6969(6) ?, β = 97.057(2)°, V = 4909.4(4) ?³, space group P2₁/c, Z = 4, ρ_calcd = 1.507 g/cm³, R = 0.0556. The crystals of compound II are triclinic, a = 11.7784(3), b = 12.1760(3), c = 13.1922(2) ?, α = 85.5420(10)°, β = 87.9000(10)°, γ = 70.3680(10)°, V = 1776.46(7) ?³, space group P , Z = 1, ρ_calcd = 1.444 g/cm³, R = 0.0350. Original Russian Text ? E.A. Gerasimova, T.V. Utkina, E.V. Peresypkina, A.V. Virovets, T.G. Cherkasova, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 5, pp. 751–755.     

Structure and luminescence of [Tb0.5(C6NO2H5)3(H2O)2]2n·(H3O)4n(ZnCl5)n(ZnCl4)2n

A novel bimetallic 4f-3d metal-isonicotinic acid inorganic-organic hybrid complex [Tb_0.5(C₆NO₂H₅)₃(H₂O)₂]_2n ·(H₃O)_4n (ZnCl₅) _n (ZnCl₄)_2n (1) is synthesized. It has a one-dimensional polycationic chain-like structure. Photoluminescent investigation reveals that it displays interesting emissions in the violet, blue, green, and yellow regions.     

四核铁配合物[Fe4(NTB)4(μ2-O)2(μ4-Suc)](ClO4)6促进DNA水解

四核铁配合物[Fe₄(NTB)₄(μ₂-O)₂(μ₄-Suc)](ClO₄)₆与DNA具有较强的结合作用，结合常数k_{b达(5.9±0.4)×10⁵ L·mol^-1。该多核铁配合物由水解途径促进DNA断裂，在酸性及低离子浓度条件下的促进作用较为显著。动力学分析表明DNA水解没有明显的序列选择性，质粒DNA从超螺旋转变为切口形式符合饱和酶动力学规律，饱和速率常数ksat=0.014 min^-1。}     

Crystal structures of barium bis(iminodiacetato)cobaltates(III): [Ba(H2O)6][Co(Ida)2]2 · H2O and Ba4(H2O)14][Co(Ida)2]5(ClO4)3 · 5.46H2O · 2CH3OH

The structures of the crystals of Ba₄[trans(N)-Co(Ida)₂]₃[cis-(N)-Co(Ida)₂]₂(ClO₄)₃ · 19.46H₂O · 2CH₃OH (I) and Ba[trans-(N)-Co(Ida)₂]₂ · 7H₂O (II) (H₂Ida is iminodiacetic acid) were determin by X-ray diffraction. The crystals of I containing two geometric isomers of the complex anions [Co(Ida)₂]⁻ were obtained by a slow cooling of a hot solution, which contained initially only the cis-isomer. One Ba atom in I interacts with the trans-complex and with two cis-complexes to give a three-dimensional framework in crystal I. The positive charge of the last framework is compensated by one more trans-complex and by the perchlorate ions, one of which acts as a bidentate ligand with respect to the Ba atom. The crystals of II are built of the chains with the alternating Ba atoms and the trans-(N)-[Co(Ida)₂]⁻ anions. The other anions of the same structure are each “suspended” to the Ba atoms of the chain. Original Russian Text ? M. Zabel, A.I. Poznyak, V.I. Pawlowskii, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 11, pp. 831–836.     

Solid-state cis-trans isomerization reaction of (η-MeC5H4)W(CO)2P(OPr)3I

cis-(η⁵-MeC₅H₄)W(CO)₂P(OⁱPr)₃I (1) was converted to the trans isomer 2 in the solid state (90-110 °C). The reaction was monitored by heating 1 in NMR tubes for periods of time (2-60 min), cooling the tubes to room temperature and determining the conversion by solution ³¹P and ¹H NMR spectroscopy. The data were consistent with a first-order reaction and yielded an activation energy of 59 ± 3 kJ mol⁻¹. Comparative kinetic data were obtained from an in situ analysis of a powder-XRD study of 1. The powder-XRD study was conducted at 80-100 °C (10-60 min), yielding an activation energy of 52 ± 2 kJ mol⁻¹ (first-order reaction). The reaction could not be monitored by single crystal X-ray diffraction as the crystal disintegrated over time on heating. This disintegration process was monitored by optical microscopy and revealed that while the bulk crystal morphology was retained the crystal surface roughened with time. The compounds 1 and 2 were also structurally characterised by X-ray crystallographic techniques.     

配合物{(n-Bu)2Sn[(η5-C5H5)Fe(η5-C5H4)COO]2}2的合成、谱学表征及晶体结构

合成了新型配合物{(n-Bu)₂Sn[(η⁵-C₅H₅)Fe(η⁵-C₅H₄)COO]₂}₂，用元素分析、红外光谱和核磁共振谱( ¹H、¹³C、¹¹⁹Sn)进行了表征，并用X-射线单晶衍射分析法测定其晶体结构。晶体属单斜晶系，空间群P2₁/c，晶胞参数a=11.753(4)?，b=21.133(7)?，c=23.374(9)?，β=101.62(3)°，V=5687(4)?³，Z=4，D_c=1.614Mg·m^-3，μ(MoKα)=1.912mm^-1，F(000)=2800，最终可靠因子R₁=0.0827，wR₂=0.2085。配合物分子呈中心对称，是具有Sn₂O₂中心内环的二聚体结构;每个锡原子与5个O原子和2个C原子形成扭曲的五角双锥几何构型，其中5个O原子为赤道配位原子，而C-Sn-C为配合物的轴。     

三维异核Mn-Na配合物[MnNa(N3)4(C5H5N)4]的合成与表征

Azide-containing coordination polymers have received considerable attention for the construction of new molecule-based magnets. A three dimensional heteronuclear Mn-Na compound [MnNa(N₃)₄(C₅H₅N)₄] was obtained by reaction of [Mn₃O(O₂CCH₃)₆(py)₃]ClO₄ and NaN₃ in pyridine solvents. The title compound crystallizes in monoclinic space group C2/c, a=1.536 6(2), b=1.045 3(2), c=1.576 3(2) nm, β=90.309(3)°, V=2.531 8(6) nm³, Z=4. In the structure, each Mn³⁺ and Na⁺ ion coordinated with four N atoms from four N₃^- and two N atoms from two pyridine molecules. Each pair of Mn³⁺ and Na⁺ ion are linked by N₃^- bridges into a 3D polymer with PtS topology. CCDC: 706250.     

Cyclopentadienyl chromium and tungsten complexes with halide, methyl and σ-phenylethynyl ligands: Structures of (η-C5H5)Cr(NO)2(-CC-C6H5), (η-C5H5)Cr(NO)2I and [(η-C5H4)-COOCH3]W(CO)3Cl

With copper(I) iodide as catalyst, σ-alkynyls, compounds (η⁵-C₅H₅)Cr(NO)₂(CC-C₆H₅) (5), [(η⁵-C₅H₄)-COOCH₃]Cr(NO)₂(CC-C₆H₅) (10), and [(η⁵-C₅H₄)-COOCH₃]W(CO)₃(CC-C₆H₅) (13), were prepared from their corresponding metal chloride 1, 6 and 12. Structures of compound 3, 5 and 12 have been solved by X-ray diffraction studies. In the case of 5, there is an internal mirror plane passing through the phenylethynyl ligand and bisecting the Cp ring. The phenyl group is oriented perpendicularly to the Cp with an eclipsed conformation. The twist angle is 0° and 118.4° for -CC-Ph and two NO ligands, respectively. The orientation is rationalized in terms of orbital overlap between ψ₃ of Cp, dπ of Cr atom, and π^∗ of alkynyl ligand, and complemented by molecular orbital calculation. The opposite correlation was observed on the chemical shift assignments of C(2)-C(5) on Cp ring in compounds 6 and 12, using HetCOR NMR spectroscopy. The electron density distribution in the cyclopentadienyl ring is discussed on the basis of ¹³C NMR data and compared with the calculations via density functional B3LYP correlation-exchange method.     

LaL3(NO3)3·(H2O)2·(C2H5OH)2的晶体结构和生成反应焓变

0 引言 稀土是一类具有特殊结构和性质的元素,稀土元素不仅大量用于工业,而且在农业和医学领域也有广泛应用 [1,2].其中,镧系离子以其独特的光、电、磁、催化和分析等性能而受到人们的广泛关注,并进行了大量的研究.镧系离子本身发光效率低,目前,设计并合成含有稀土离子La3+和Eu3+的超分子配合物,作为发光分子器件和荧光探针成为稀土配位化学,材料科学,超分子化学,分析化学和生物化学等研究领域的热点课题之一 [3～8].但对它们的热化学行为的研究鲜见文献报道.     

Synthesis and crystal structure of [Fe4O2(H2O)10(C5H5NCOO)4](NO3)8 · 2H2O

Crystals of the tetranuclear complex [Fe₄O₂(H₂O)₁₀(C₅H₅NCOO)₄](NO₃)₈ · 2H₂O are obtained by the slow evaporation of an aqueous solution of iron(III) nitrate and isonicotinic acid. According to the X-ray diffraction data, four metal atoms lie in the same plane and together with two μ₃-O oxygen atoms form the fragment [Fe₄(μ₃-O)₂]¹⁰⁺. The [Fe₄O₂(H₂O)₁₀(C₅H₅NCOO)₄]⁸⁺ cation has been obtained and structurally characterized for the first time.     

超分子配合物[Co(H2O)6]·(Hnip)2·(H2nip)2·(CH3NHCH3)2·(H2O)8的直接合成，晶体结构和热分解反应动力学(nip=5-nitroisophthalate)

用直接法培养了配合物[Co(H₂O)₆]·(Hnip)₂·(H₂nip)₂·(DMA)₂·(H₂O)₈(DMA=CH₃NHCH₃)的晶体并用X射线单晶衍射，元素分析和傅里叶变换红外光谱进行了表征。该晶体属于三斜晶系，P-1空间群，晶胞参数为a=0.7012(1)nm, b=1.1378(2) nm, c=1.6612(3) nm, α=84.92(3)º, β=85.19(3)º,γ=85.91(3)º。晶胞体积V=1.3128(5) nm³, Z=1, 理论密度D_c=1.573 g/cm³. 最终R因子[I>2σ(I)]为: R₁=0.0279,wR₂=0.0765; 所有衍射点的R因子为: R₁=0.0327, wR₂=0.0806.衍射结果表明，在晶体结构中两个Hnip分子，两个H₂nip分子，两个DMA分子和八个水分子通过氢键和π-π堆积作用连接到每个Co配位八面体中心上。对配合物进行了DSC和TG-DTG热分析，根据热分析结果推测得到配合物的热分解机理，并且用Kissinger,Ozawa，积分法和微分法确定了最可能的动力学模型函数。